Valkiriforce recently mentioned that Chocolate Doom has been crashing in a certain section of Interception Map28 (in the red cave in the structure left of the starting area with all the archviles ). Upon closer inspection I found out that the game crashes whenever certain linedefs in the area (such as linedef 8018) are hit by hitscan weapons. Does anyone know what could be the cause of this bug?

An Intercepts overflow (though more famous for "allghosts") often causes a crash, in vanilla at least. See what happens in prboom-plus (with -complevel 2 and making sure intercepts overflow emulation is turned on, naturally).